What chemicals can be involved?
The chemical that were involved are stack of mud and organic remains many kilometres thick can pile up on sea floors, especially in nutrient-rich waters. They do overlying sediments that are continuously being deposited will lie to rest these organic remains and mud so deeply that eventually and can be change into solid rock. Because the high heat and intense pressure help it next to various chemical reactions, transform the soft parts of ancient organisms found in the sea-bed slush into oil and natural gas. At this position, this ooze at the floor of the ocean becomes into foundation rock.
The bad thing of the oil spill is that animals and creatures in the water will suffer because the oil will spread to half the water
Why are these chemicals bad for the environment and its animals?
"This study shows that it is very possible that openness to Exxon Valdez oil is having a material impact on many adventurous animals and is contributing to their slow recovery in some parts of Prince William Sound," Short said. "Sea otters, for instance, have yet to re-inhabit Herring Bay, the most oiled bay we studied, and the population of otters elsewhere around northern Knight Island continues to decline. Unfortunately, because much of this oil is buried in beach sediments and not exposed to weathering and other elements that might degrade it, it could remain hazardous to wildlife for decades. The Exxon Valdez affected many animals at Prince William Sound in Alaska. The spill greatly affected sea otters and sea birds. There were about 2,800 sea otters and 250,000 seabirds killed by the spill. Harbor seals, bald eagles, killer whales, and salmon were also greatly affected by the spill.
Many people complained about the large amount of sea otters dumped in crude oil because Prince William Sound was a tourist attraction. Many people came to Prince William Sound to visit the animals.

The study, by chemist Jeffrey Short,
Bibliography:
http://www.priweb.org/ed/pgws/systems/maturation/maturation.html
http://news.mongabay.com/2006/0516-exxon.html